Modal verbs have to and has to
Use have to or has to plus the base form of a verb to show that something is necessary (very important).
You have to take History and Science to graduate.
I have to work at the office today.
We have to study for the test this weekend.
My parents have to leave for the airport at 6:00.
She has to finish her homework before she can go out.
Jose has to take his medicine with food.
Use don't have to or doesn't have to to show that something is not necessary.
You don't have to answer all the questions. You can choose just two.
Miriam doesn't have to work tonight.
For questions, use Do or Does and have to:
Do we have to finish the project today?